The present invention relates to floating structures. In particular, the present invention relates to floating structures useful for maintaining platforms supporting airplane runways, bridges, or other structures afloat in bodies of water.
Constraints such as shortages of available land when there is a need to locate a structure, either temporarily or permanently, either adjacent to land, or in a large body of water, have led to the development of floating platforms and the like that can support a structure on a body of water. For example, floating runways such as that disclosed in U.S. Pat. No. 5,906,171 provide water-borne surfaces for aircraft to land and take off, similar to surfaces on aircraft carriers. Floating airports, such as that disclosed in U.S. Pat. No. 5,398,635, can further include means for controlling the position of a floating airport by compensating for disturbances to such position by prevailing winds and currents. Complex structures, such as those disclosed in U.S. Pat. No. 5,799,603, have also been developed to provide stability under ocean conditions. According to the disclosure of the ""603 patent, energy due to striking waves is partly absorbed by a buoyant load-bearing assembly that includes universal joints and shock-absorbing hydraulic cylinders.
Similarly, floating bridges and roadways have been developed for use in, for example, locations where conventional bridge construction and/or maintenance would be undesirably costly or difficult, or where a relatively short bridge span is required. The ability to transport such floating bridges to a site has been facilitated by utilizing foldable hulls, as described in U.S. Pat. No. 4,561,376, or by providing an amphibious vehicle that can be equipped with hulls and can function as a bridge or portion thereof, as described in U.S. Pat. No. 4,621,385. Such structures, while portable, are apparently somewhat complex.
It will be appreciated that in any geographic area adjacent to bodies of water, where land is scarce or not available for development, floating platforms may be desirable. Development of additional permanent or temporary facilities for manufacturing, power generation, housing or other commercial use may be desirable, but not practical in view of land use policies or community opposition. In the international context, there may be a need for facilities, such as airfields and housing facilities, for military and/or relief efforts, which cannot be located on land because of political and security concerns.
A need remains for floating structures supporting floating platforms suitable for use as aircraft landing strips, airports, roadways, bridges and off-shore facilities. A need also remains for such floating structures that are not subject to some motion caused by waves or water currents as to fail to be functional for their intended purposes. The present invention is directed to these and other objectives.
One aspect of the invention is a floating structure comprising at least one deck; one or more flotation means attached to and supporting the deck; means for reducing the effects of currents in a body of water on the flotation means; and mooring means for restricting translational motion of the floating structure. In some embodiments, the means for reducing the effects of currents include ballast means for controlling flotation of the structure in a body of water; and mooring means for restricting translational motion of the floating structure.
A further aspect of the present invention is a floating structure that includes at least one deck having an upper surface and a lower surface; one or more pontoons having an interior chamber, attached to and supporting the deck; and a basin. The pontoon chamber is of sufficient volume to cause the deck, the pontoon and its load to float. The basin contains basin water that surrounds the pontoons, and has an open top, and the pontoons float in the basin water. The basin has a chamber of sufficient size to cause the basin to float in a body of water. Preferably, the basin has a wall sufficiently high to isolate the basin water from the body of water.
In some embodiments, the deck has at least two ends, the ends each being attached to a substantially fixed structure, thereby forming a bridge. Preferably, each of the ends contacts the substantially fixed structure, such that a vehicle may be driven from the deck to the substantially fixed structure.
The basin may have a plurality of walls, or a single substantially cylindrical wall. In some embodiments, the basin wall has one or more gates therein. The gate allows for the passage of pontoons and/or basin water into or out of the basin.
Another aspect of the present invention is a method for providing a floating bridge. The method includes providing one or more floating basins having basin water therein; providing one or more pontoons floating in the basins; providing, on the pontoons, a deck having an upper surface and at least two ends; and attaching each of said at least two ends to a substantially fixed structure, thereby forming a bridge between said fixed structures. In some embodiments, the deck is movable with respect to the pontoons. The floating structure may comprise a plurality of basins, which may contain ballast.
A further aspect of the invention is a method for providing a floating runway. The method includes providing one or more floating basins having basin water therein; providing one or more pontoons floating in the basins; and providing, on the pontoons, a deck for supporting the runway. The deck may be movable with respect to the pontoons.
In some embodiments, one or more basin walls has attached thereto a mooring line. The mooring line may be removably attached to a fixed structure such as a pier.
These and other aspects of the invention will be apparent to one skilled in the art in view of the following description and the appended claims.